Evidence for Thermal-Stress-Induced Rockfalls on Mars Impact Crater Slopes
Icarus 342 (2020) 113503 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Evidence for thermal-stress-induced rockfalls on Mars impact crater slopes P.-A. Tesson a,b,*, S.J. Conway b, N. Mangold b, J. Ciazela a, S.R. Lewis c, D. M�ege a a Space Research Centre, Polish Academy of Science, Wrocław, Poland b Laboratoire de Plan�etologie et G�eodynamique UMR 6112, CNRS, Nantes, France c School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK ARTICLE INFO ABSTRACT Keywords: Here we study rocks falling from exposed outcrops of bedrock, which have left tracks on the slope over which Mars, surface they have bounced and/or rolled, in fresh impact craters (1–10 km in diameter) on Mars. The presence of these Thermal stress tracks shows that these rocks have fallen relatively recently because aeolian processes are known to infill Ices topographic lows over time. Mapping of rockfall tracks indicate trends in frequency with orientation, which in Solar radiation � � turn depend on the latitudinal position of the crater. Craters in the equatorial belt (between 15 N and 15 S) Weathering exhibit higher frequencies of rockfall on their north-south oriented slopes compared to their east-west ones. � Craters >15 N/S have notably higher frequencies on their equator-facing slopes as opposed to the other ori entations. We computed solar radiation on the surface of crater slopes to compare insolation patterns with the spatial distribution of rockfalls, and found statistically significant correlations between maximum diurnal inso lation and rockfall frequency.
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